Patent GB-197352-A (GB)
Abstract: 197,352. Chase, G. C. Dec. 6, 1921. Multiplying and dividing apparatus.-In machines for the four rules, such as those of the type described in Specifications 27231/12, 157,845 and 192,433 provision is made for performing calculations involving British-currency or other non- uniform systems by either the fractional or decimal method. According to the invention, the totalizer-counter carriage is selectively movable to vary the groups of totalizer numeral wheels adapted to the different systems of numeration so as to bring them under control of the differentialactuating mechanism, and the key-board is provided with various interlocking arrangements for certain banks of keys in accordance with the position of the carriage. The carriage is raised and shifted by means of a knob 90, Figs. 1 and 21, and in the position for decimal calculation a detent 85 pivoted to the carriage engages the end of the carriage stop spring 92 which surrounds the rod 84 on which the, carriage, is freely pivoted. In order to move the carriage farther to the left into " fractional " position a plunger 80 mounted in the knob 90 must be depressed so as to raise the detent 85 to allow the end of the casing to engage the stop spring. In alignment with the usual revolutions or quotients counter 93 is a numeral wheel 92 which is provided for the purpose of counting the additions or multiplications of British currency calculations. The wheel 92 is marked with numerals " 0-19 " but it may be replaced by an ordinary counter and is actuated by a pawl on an arm operated by a cam on the mainshaft. Differential mechanism.-The differential actuating mechanism is similar to that described in Specification 27231/12, but is modified as described in Specification 195,964 to adapt the construction to the British monetary system. Keyboards; interlocking.-The four right hand numeral wheels 1, 4, 7, 8 for the farthings, pence and shillings function only when the carriage 12, Fig. 1, is in its extreme left hand position that is the British currency position wherein the farthings keys 13, and pence keys 14 and 15 are operative to set the corresponding differential mechanism. The. units of shillings keys 16 and the tens of shillings key 17 have the digits differently coloured from those of the other banks and in this position of the carriage the "2-9" keys 18 in the tens of shillings bank are locked by means. of a detent bar 33 operatively connected by means of a pivoted lever 45, Fig. 14, and a lever 42, Fig. 15, to a locking bar 39 adapted to be reciprocated by a lever 37 having an upstanding cam surface 36 engaged by a pin 28 on the carriage in its " fractional " position. Each bank of keys is provided with the usual detent plate 20 and a single release bar 21 is provided which in addition to its being operated, to release the depressed keys, as described in the aforesaid Specifications, is operated on the shifting of the totalizing-counter carriage to the " fractional " or " decimal " position or viceversa by means of a cam 30<1> on a lever 30 pivoted to a bridge-member 27 on the key-board framework and having an arm engaging a slot in the end of a lever 32 connected to the release bar 21. For the " 10 " and " 11 " pence keys the detent plate thereof is connected by a link to the detent plate 20 of the other pence keys. The length of the bridge 27 is sufficient to hold the carriage in its inoperative raised position while being shifted the two steps to throw the numerals wheels 1, 4, 7, 8 into inactive position, the units of shillings keys 16 serving as the units bank for " decimal " calculations. This movement releases the '' 2-9 " keys 18 and locks the farthings and pence keys 13, 14, 15 by means of detent bars 48 actuated by projections 49 on the locking bar 39. The detent bars 33 and 48 are brased by means of extensions 50 on the release bar 21, Fig. 16. Punctuation.-Decimal markers 54 are provided between each band of keys to the left of the units of shillings bank 16 except between the tens of shillings key 17 and the next higher denomination where there are provided two markers 55, 56, Fig. 20, which overlie each other and are adapted to be turned over upon each other. These markers are pivoted strips of metal which can be turned through an angle of 180‹ and have a colour on one side contracting with that of the keyboard. The markers 55, 56 are coaxial and independently movable and the marker 55 is movable automatically to display the distinctive colour when the. carriage is shifted to " fractional " position by means of a pinion 57 on the axle thereof which engages a sector 58 pivotally connected to a link 61, Fig. 18, having a forked extension 63 engaging the rear end of the lever 37. Specifications 14152/13 and 192,434 are referred to.